A review on wideband microstrip patch antenna design techniques

This review article presents an overview of the design techniques for broadband microstrip patch antennas. Basically, a microstrip patch antenna is composed of a trace of copper or any other metal of any geometry on one side of a standard printed circuit board (PCB) substrate with other side grounded. This antenna can be fed using coaxial, stripline, aperture-coupling or proximity-coupling methods. The idea of patch antenna slowly attracted the antenna community in 20 years after its birth in early 50's. The patch antennas are very useful because of their; low weight, ability to conform to any geometrical shape, easy integration with HMICs and MMICs, and low cost fabrication. Their major drawback is their narrow bandwidth which makes them unsuitable for modern-day wireless communication technologies. Through extensive studies in the last few decades on antenna performance improvement, various techniques have been developed to enhance the bandwidth. The current research focus is on the reconfigurable antennas. These can provide wide bandwidth performance; multi-band functionality; the frequencies and bandwidths can be reconfigured as well. The microstrip antennas are widely used in military, industrial and commercial sectors. This article opens with short introduction of basic characteristics, feeding methods and analysis techniques of patch antenna. After that review of bandwidth enhancement techniques, multi-band and wideband reconfigurable antenna designs are presented. The article closes with conclusions and future perspective.